OBD-II code · Powertrain (generic)
P0159 O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
The ECU detects an abnormally high voltage from the downstream O2 sensor on bank 2. Indicates persistently rich exhaust past the cat, shorted sensor or wiring shorted to voltage.
Is it safe to drive with P0159?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyRich condition on bank 2
- PossibleSignal wire shorted to voltage
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor B2s2, Oxygen Sensor Wiring
Related codes
- P0139O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
- P0145O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)
- P0153O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
- P0165O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)
- P0156O2 Sensor Circuit Malfunction (Bank 2, Sensor 2)
- P0157O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
- P0158O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
- P015AO2 Sensor Delayed Response - Rich to Lean Bank 1 Sensor 1
- P015BO2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 1
- P015CO2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.